1. Field of the Invention
The present invention relates to a system and method for forming a structural connection, and more particularly to a system and method for embedding connecting members into masonry walls or other such building structures.
2. Description of Prior Art
Building constructions typically include connections between various structures such as walls, floors and roofs. For example, in some building designs, the roof lies below the top of exterior walls, creating a parapet around the building. These designs require the use of a horizontal support to hold the roof structure. The horizontal support is usually a beam or some type of ledger.
In masonry constructions, ledgers are elongate wood members or steel pieces with angle iron configurations. Anchor bolts attach the wood legers to a wall structure in the same manner that Nelson studs attach the steel ledgers to a wall. As shown in FIG. 1, Nelson studs lie welded to the back of the steel angle iron and extend into a masonry structure.
In securing a wood ledger to a wall structure one would install the anchor bolts into the hollows of masonry units, pour grout or concrete into the hollows of the masonry units, adjust the bolts to place them in proper positions, drill the wood member with openings for the bolts, slip the bolts through the openings in the wood member, and secure the wood member to the wall with nuts and washers. The prior method of securing a metal ledger to a wall unit has a similar set of steps.
Prior to 1988, the holes that received the anchor bolts and Nelson studs in the masonry units had a size that was large enough to merely accommodate the bolts and studs. However, after 1988, building codes required “[a]ll bolts to be grouted in place with at least 1 inch of grout between the bolt and the masonry” (see FIG. 2). This change in the building code required, in essence, suspension of the anchor bolts or the Nelson studs of a steel ledger in the larger holes until the grout or concrete secured them in this position.
One prior method of accomplishing this result with a steel ledger includes drilling holes in the masonry above and below the steel ledger, placing wire through the holes and around the ledger, and tying the wire to secure the ledger to the masonry (see FIG. 3). The disadvantage to this approach is having to perform additional procedures such as cutting and removing the wire. Also, the holes in the masonry require patching in applications where the masonry remains exposed.
A second prior method of suspending the Nelson bolts of a steel ledger involves positioning a temporary wood support such as a two-by-four perpendicularly to the ledger (or generally parallel to the face of the masonry wall), as shown in FIG. 4, and securing the support with shot pin nails. This procedure has a number of disadvantages. First, it requires a supply of wood which increases the cost of the procedure. Also, it requires the removal of the temporary supports and the patching of holes left by the shot pin nails.
Another prior method similar to the second approach outlined above involves inserting anchor bolts into a wood ledger prior to its placement and using wood elements and shot pins through the elements and the ledger to support the wood ledger. The arrangement provided by this method is similar to the one shown in FIG. 4, and it suffers the same disadvantages. It requires an additional supply of wood; and it requires the removal of temporary supports and the patching of holes left by the shot pin nails.
The system and method of the present invention avoids the disadvantages of the prior art systems and methods. It allows quick and easy installation of masonry ledgers or other such connectors. It does not require temporary supports or removal of any materials after it fulfills its temporary function of suspending the ledger to allow grout or concrete placement. It is a simple and cost-effective approach to ledger installation which minimizes the cost of labor and the cost of materials.